Electric pump

ABSTRACT

An electric pump includes: a pump unit; a motor unit configured to drive the pump unit; a control unit configured to control driving of the motor unit; and a resin-made housing configured to accommodate the control unit, in which the housing has a housing main body and a cover body, the cover body includes, on an inner surface side thereof, a metal portion which entirely covers at least one surface portion of a control board configuring the control unit, and the metal portion is configured to be groundable.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. § 119to Japanese Patent Application 2018-039949, filed on Mar. 6, 2018, theentire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to an electric pump having a pump unit, a motorunit for driving the pump unit, a control unit for controlling drivingof the motor unit, and a housing for accommodating the control unit.

BACKGROUND DISCUSSION

In the electric pump, a control unit for controlling driving of themotor unit is configured to include a control board on which anelectronic component, for example, such as a FET element configuring aswitching circuit is mounted. Reference 1 (JP 2016-8526A) discloses theelectric pump in which a housing for accommodating the control board isdisposed on one end side of a motor housing for accommodating the motorunit.

According to the electric pump disclosed in Reference 1, the housingincludes a resin-made housing main body having an opening portionthrough which the control board is externally visible and a cover bodyfor closing the opening portion. The cover body includes a resin-madeframe-shaped portion to be attached to the housing main body by means ofthermal welding and a metal-made radiator plate for closing an innerperipheral side of the frame-shaped portion. A band plate-shaped fixingportion to be fastened to a transmission by using a bolt is integrallydisposed in the radiator plate by means of welding, and the radiatorplate and the control board are electrically connected to each other bya connection member interposed between both of these. In this manner,even if noise is generated on the control board, the control board isgrounded via the radiator plate, the fixing portion, and thetransmission. Accordingly, the noise flows from the radiator plate tothe transmission. As a result, outward emission of the noise generatedon the control board is reduced. Therefore, it is possible to prevent adisadvantage that an external device is adversely affected by the noise.

However, according to the electric pump disclosed in Reference 1, themetal-made radiator plate included in the cover body has a structurewhich is exposed outward. Accordingly, in some cases, the radiator plateis degraded by receiving influence of salt damage, chemicals, or gasfrom an outer surface thereof. If the radiator plate is degraded, aresistance value of the radiator plate increases, thereby causing apossibility that the control board may be adversely affected or theradiator plate may be damaged by receiving the influence of vibrationsor stepping stones. In addition, the cover body has the resin-madeframe-shaped portion and the metal-made radiator plate. Accordingly, dueto a difference in expansion coefficients of mutually differentmaterials, a gap is sometimes formed between the resin portion and theradiator plate, depending on a temperature. In this case, there is apossibility that moisture may enter the control unit through the gap andthe control unit may be adversely affected. Therefore, in the electricpump, there is room for improvement in configuring the housing foraccommodating the control unit.

Thus, a need exists for an electric pump which is not susceptible to thedrawback mentioned above.

SUMMARY

A feature of an electric pump according to an aspect of this disclosureresides in that the electric pump includes a pump unit, a motor unitconfigured to drive the pump unit, a control unit configured to controldriving of the motor unit, and a resin-made housing configured toaccommodate the control unit. The housing has a housing main body and acover body. The cover body includes, on an inner surface side thereof, ametal portion which entirely covers at least one surface portion of acontrol board configuring the control unit. The metal portion isconfigured to be groundable.

According to this configuration, the resin-made housing foraccommodating the control unit has the housing main body and the coverbody. The inner surface side of the cover body includes the metalportion which covers at least the one entire surface portion of thecontrol board configuring the control unit. The metal portion isconfigured to be groundable. In this manner, even if noise is generatedin an electronic component on the control board, noise can be releasedfrom the metal portion toward the ground. Accordingly, the outwardemission of the noise generated in the control unit is reduced. As aresult, it is possible to prevent the noise from influencing outward ofthe control unit, and it is possible to improve noise immunity of thecontrol unit.

In addition, a configuration is adopted in which the metal portion whichreduces the outward emissions of the noise generated in the controlboard is located on the inner surface side of the cover body and is notexposed outward. Accordingly, even if the cover body is affected by anexternal environment, it is possible to prevent a disadvantage that themetal portion may corrode or may be damaged. Furthermore, the surface ofthe cover body is formed of only the resin. Accordingly, there is littlepossibility that moisture may enter the control unit from the outsidevia the cover body.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and additional features and characteristics of thisdisclosure will become more apparent from the following detaileddescription considered with the reference to the accompanying drawings,wherein:

FIG. 1 is a longitudinal sectional view illustrating an electric pumpaccording to a first embodiment;

FIG. 2 is a schematic view illustrating a main part according to asecond embodiment;

FIG. 3 is a schematic view illustrating a main part according to a thirdembodiment;

FIG. 4 is a schematic view illustrating a main part according to afourth embodiment; and

FIG. 5 is a schematic view illustrating a main part according to a fifthembodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments disclosed here will be described with referenceto the drawings.

First Embodiment

As illustrated in FIG. 1, an electric pump 100 is configured so that apump unit P, a motor unit M for driving the pump unit P, and a controlunit D for controlling driving of the motor unit M are accommodated in acase C. For example, the electric pump 100 is bolted and fixed to a caseof a transmission E of a vehicle transmission, and is used in order topump lubricating oil of the transmission E as hydraulic operating fluidto hydraulic equipment inside a vehicle.

The case C is configured so that a flat base plate 1, a pump housing 2for accommodating the pump unit P, and a main housing 3 (example of ahousing) for accommodating the motor unit M and the control unit D areintegrally connected to each other. The base plate 1 and the pumphousing 2 are formed of an aluminum alloy. The case C is fixed to thecase of the transmission E by using a bolt 26. The transmission E isgrounded.

The pump unit P is configured to include a trochoid pump including aninner rotor 9 rotated by a driving force of a shaft 11 and an outerrotor 10 located outside the inner rotor 9. Inside the pump housing 2,the outer rotor 10 is located so as to be freely rotatable together in astate of being eccentric from a rotary shaft core X of the inner rotor9.

The motor unit M is configured to include a brushless DC motor whoserotation is controlled by the control unit D. The motor unit M includesa shaft 11, a motor rotor 4, and an annular stator 12. The shaft 11 issupported so as to be rotatable around the rotary shaft core X. Themotor rotor 4 is rotated integrally with the shaft 11. The stator 12 isaccommodated in a region surrounding the motor rotor 4 inside acylindrical housing main body 7.

The stator 12 includes a stator core 13, an insulator 14, and a coil 15via a gap outside an outer peripheral surface of the motor rotor 4. Thestator core 13 is configured so that electromagnetic steel plates arestacked one on another, and a plurality of salient poles (teeth) aredisposed toward the motor rotor 4. The resin-made insulator 14 ismounted on each tooth of the stator core 13 from both end sides in anaxial direction. The coil 15 is wound around the insulator 14. The motorrotor 4 has a rotor core including a plurality of permanent magnets 4Ainside a stacked structure of the multiple electromagnetic steel plates.

The control unit D for controlling the driving of the motor unit M isconfigured to include a control board 5. The main housing 3 correspondsto the housing for accommodating the control unit D. The main housing 3is made of a thermoplastic resin, and includes a housing main body 7 anda cover body 8. The housing main body 7 accommodates the motor unit M,and the cover body 8 is assembled to an opening end portion 7a on a sideof the housing main body 7 which is opposite to the pump housing 2. Thecontrol board 5 is accommodated inside a space surrounded by the housingmain body 7 and the cover body 8.

In addition to a power control element, a capacitor, and a resistor, anelectronic component 16 such as a FET element 17 of a switching circuitfor determining a power control timing is mounted on the control board5. The control unit D functions to generate a rotating magnetic field bysequentially supplying electric power to the coil 15, and controlsrotation speed of the motor rotor 4 by controlling a rotation speed ofthe rotating magnetic field.

The housing main body 7 and the cover body 8 are joined to each otherthrough welding (for example, hot plate welding, ultrasonic welding,vibration welding, or infrared welding) by heating and pressurizingresins. The cover body 8 has a ventilation hole (not illustrated)through which an external space and an internal space of the mainhousing 3 communicate with each other. In this manner, the ventilationhole adjusts a pressure difference between the internal space and theexternal space of the housing main body 7 which is caused by a rapidtemperature change of the motor unit M under an environment of using theelectric pump 100. A filter (not illustrated) for covering theventilation hole is fixed to an inner surface of the cover body 8. Theventilation hole blocks moisture and allows only air to passtherethrough by using the filter.

The cover body 8 includes a metal portion 41 which covers at least oneentire surface portion 5A of the control board 5 on an inner surfaceside 8A. The metal portion 41 has a top surface portion 42 for coveringthe one surface portion 5A of the control board 5 and a tubular portion43 erected from a peripheral edge of the top surface portion 42 to aside of the control board 5. The tubular portion 43 is formed so as tocover an entire side portion 5C of the control board 5. The metalportion 41 is formed of a metal material such as an aluminum alloy,iron, and copper.

A connection member 45 (example of a first connection member) forelectrically connecting the metal portion 41 and the control board 5 toeach other is provided between the metal portion 41 and the controlboard 5. The connection member 45 is formed of a metal material which isthe same as that of the metal portion 41. For example, the connectionmember 45 is formed in a Z-shape in a side view so as to reliably comeinto contact with the metal portion 41 and the ground pattern 51 of thecontrol board 5, and is configured to be elastically deformable.

The motor unit M has an extension member 31 extending from the statorcore 13 of the stator 12 to the side of the control board 5 andelectrically connected to the stator core 13 (stator 12). The extensionmember 31 is formed of a metal material which is the same as that of themetal portion 41. For example, the extension member 31 is formed in atubular shape, and has a plurality of fastening portions 32 for fixingthe control board 5 to one end on the side of the control board 5. Thecontrol board 5 is screwed and fixed to the fastening portion 32 byusing a metal-made screw member 33. The ground pattern 51 disposed inthe control board 5 and the extension member 31 are electricallyconnected to each other via the screw member 33 fixed to the fasteningportion 32. The extension member 31 and the screw member 33 correspondto a second connection member for electrically connecting the stator 12and the control board 5 to each other. In the present embodiment, asillustrated in FIG. 1, an end portion 43 a of the tubular portion 43 ofthe metal portion 41 and an end portion 31 a of the extension member 31on the side of the control board 5 overlap each other when viewed in theradial direction of the tubular portion 43.

A connection member 46 for electrically connecting the stator 12 and thepump housing 2 to each other is provided between the stator 12 and thepump housing 2. The connection member 46 is formed of a metal materialwhich is the same as that of the metal portion 41. In this manner, themetal portion 41 has a conduction path connected to the pump housing 2via the connection member 45, the ground pattern 51 of the control board5, the extension member 31, the stator 12, and the connection member 46.The metal portion 41 is configured to be electrically groundable. Thepump housing 2 is electrically connected to the transmission E groundedby using a bolt 26. Accordingly, even if noise is generated in theelectronic component 16 on the control board 5, the noise can bereleased to the ground from the metal portion 41 via the transmission E.Accordingly, outward emission of the noise generated in the control unitD is reduced. As a result it is possible to prevent the noise frominfluencing outward of the control unit D, and it is possible to improvenoise immunity of the control unit D.

In addition, according to the present embodiment, the metal portion 41has the top surface portion 42 and the tubular portion 43. The topsurface portion 42 covers the one surface portion 5A of the controlboard 5, and the tubular portion 43 covers the entire side portion 5C ofthe control board 5. In this manner, the metal portion 41 can reduce theoutward emission of the noise by using the tubular portion 43 not onlyin a site facing the control board 5 but also around the control board5.

Furthermore, according to the present embodiment, the end portion 43 aof the tubular portion 43 of the metal portion 41 and the end portion 31a of the extension member 31 overlap each other when viewed in theradial direction of the tubular portion 43. In this manner, at least oneof the tubular portion 43 and the extension member 31 is located aroundthe control board 5. Accordingly, the outward emission of the noise ofthe control unit D can be more reliably reduced, and the noise immunityin the control unit D of the electric pump 100 is further improved.

Second Embodiment

FIG. 2 illustrates a second embodiment of the electric pump 100.

According to the second embodiment, as illustrated in FIG. 2, unlike thefirst embodiment, the connection member 45 is not disposed between themetal portion 41 and the control board 5. The end portion 43 a of thetubular portion 43 of the metal portion 41 and the end portion 31 a ofthe extension member 31 are electrically connected to each other. Atleast any one of the end portion 43 a of the tubular portion 43 and theend portion 31 a of the extension member 31 may have an elasticallydeformable elastic portion. In an example illustrated in FIG. 2, the endportion 43 a of the tubular portion 43 is configured to serve as theelastically deformable elastic portion.

In this way, if at least one of the end portion 43 a of the tubularportion 43 and the end portion 31 a of the extension member 31 is theelastically deformable elastic portion, even if a temperature change,vibration, or shock is applied to the electric pump 100, a connectionstate between the metal portion 41 and the extension member 31 can bemaintained. In this way, the metal portion 41 and the extension member31 are electrically connected to each other, thereby forming aconduction path connected from the metal portion 41 to the pump housing2 via the extension member 31, the stator 12, and the connection member46. The metal portion 41 is configured to be electrically groundable. Asa result, the noise generated in the control board 5 can be releasedfrom the metal portion 41 to the ground via the transmission E.

Third Embodiment

FIG. 3 illustrates a third embodiment of the electric pump 100.

In the control board 5 configuring the control unit D, variouselectronic components 16 are usually arranged on the side facing themetal portion 41. Here, as the electronic component 16, there may exista component (for example, the FET element 17 illustrated in FIG. 3)having a large projecting height from an installation surface (surfaceportion 5A) of the control board 5. In this case, the electroniccomponent 16 is likely to move close to the metal portion 41, therebycausing a possibility of short-circuiting between the metal portion 41and the electronic component 16. Therefore, according to the presentembodiment, as illustrated in FIG. 3, the cover body 8 includes acoating portion 52 for coating a side of the metal portion 41 whichfaces the control board 5. The coating portion 52 is configured to coatan entire region of the metal portion 41 excluding a connection site 47of the connection member 45. According to the present embodiment, themetal portion 41 is formed in a plate shape having only the top surfaceportion 42. Other configurations are the same as those according to thefirst embodiment.

As in the present embodiment, the cover body 8 includes the coatingportion 52. Accordingly, the metal portion 41 does not move close to theelectronic component 16 on the control board 5. Therefore, an insulationdistance can be secured between the electronic component 16 and themetal portion 41. As a result, voltage endurance characteristics of theelectric pump 100 can be improved.

Fourth Embodiment

FIG. 4 illustrates a fourth embodiment of the electric pump 100.

According to the fourth embodiment, as illustrated in FIG. 4, theelectric pump 100 is formed so that the metal portion 41 has the topsurface portion 42 and the tubular portion 43. The connection member 45for electrically connecting the metal portion 41 and the control board 5to each other is provided between the metal portion 41 and the controlboard 5. The end portion 43 a of the tubular portion 43 of the metalportion 41 and the end portion 31 a of the extension member 31 areelectrically connected to each other. Unlike the first to thirdembodiments, the control board 5 is supported by and fixed to a resinportion (for example, an insulator 14) of the motor unit M. In thismanner, a conduction path connected from the metal portion 41 to thepump housing 2 via the extension member 31, the stator 12 (stator core13), and the connection member 46 is formed. The metal portion 41 isconfigured to be electrically groundable. As a result, the noisegenerated in the control board 5 can be released from the metal portion41 to the ground via the transmission E. In addition, the metal portion41 and the control board 5 are electrically connected to each other bythe connection member 45. Accordingly, for example, when staticelectricity is generated in the control board 5, the static electricitycan be released from the metal portion 41 to the ground via thetransmission E.

Fifth Embodiment

FIG. 5 illustrates a fifth embodiment of the electric pump 100.

According to the fifth embodiment, as illustrated in FIG. 5, theelectric pump 100 is formed so that the metal portion 41 has only thetop surface portion 42. The connection member 45 is provided between themetal portion 41 and the ground pattern 51 of the control board 5. Theconnection member 48 is located between the control board 5 and the endportion 31 a of the extension member 31. The connection member 48 iselectrically connected to the ground pattern 51 of the control board 5and the extension member 31. According to the present embodiment, theconnection member 48 and the extension member 31 correspond to thesecond connection member for electrically connecting the ground pattern51 of the control board 5 and the stator 12 (stator core 13) to eachother. Similar to the fourth embodiment, the control board 5 issupported by and fixed to the resin portion (for example, the insulator14) of the motor unit M. In this manner, a conduction path connectedfrom the metal portion 41 to the pump housing 2 via the connectionmember 45 (first connection member), the ground pattern 51 of thecontrol board 5, the connection member 48, the extension member 31(second connection member), the stator 12 (stator core 13), and theconnection member 46 is formed. The metal portion 41 is configured to beelectrically groundable. As a result, the noise generated in the controlboard 5 can be released from the metal portion 41 to the ground via thetransmission E.

Other Embodiments

(1) In the above-described respective embodiments, an example has beendescribed in which the metal portion 41 or the control board 5 iselectrically connected to the pump housing 2 via the extension member31, the stator core 13, and the connection member 46. Instead of thisconfiguration, for example, a configuration may be adopted as follows.One metal member disposed on an outer peripheral side or an innerperipheral side of the stator core 13 and extending to the side of thecontrol board 5 and the side of the pump housing 2 is located betweenthe metal portion 41 or the control board 5 and the pump housing 2. Themetal portion 41 or the control board 5 and the pump housing 2 areelectrically connected to each other by the metal member.

(2) In the above-described respective embodiments, an example has beendescribed which includes the connection member 46 for electricallyconnecting the stator 12 and the pump housing 2 to each other. However,the connection member 46 may be disposed as a portion of the pumphousing 2.

(3) In the above-described respective embodiments, an example has beendescribed in which the noise generated in the control board 5 isreleased from the transmission E to the ground. Instead of theabove-described configuration, for example, a configuration may beadopted as follows. A ground line (not illustrated) of a cable whichsupplies electric power to the control unit D or communicates with ahost ECU and the ground pattern 51 of the control board 5 areelectrically connected to each other via a connector (not illustrated).In this manner, even if the electric pump 100 is not fixed to the caseof the transmission E, the noise generated in the control board 5 can bereleased from the metal portion 41 to the ground via the connectionmember 45, the ground pattern 51 of the control board 5, the connector,and the ground line.

The embodiments disclosed here can be widely used for the electric pumphaving the pump unit, the motor unit, the control unit, and the housing.

Another feature of the electric pump according to the aspect of thisdisclosure resides in that the metal portion has a top surface portionwhich covers the one surface portion of the control board, and a tubularportion which is erected on a side of the control board from aperipheral edge of the top surface portion, and the tubular portionentirely covers a side portion of the control board.

According to this configuration, the metal portion has the top surfaceportion and the tubular portion. The top surface portion covers onesurface portion of the control board, and the tubular portion covers theentire side portion of the control board. In this manner, the metalportion can reduce the outward emission of the noise generated in thecontrol board by using the tubular portion not only in a site facing thecontrol board but also around the control board. As a result, the noiseimmunity in the control unit of the electric pump is further improved.

Another feature of the electric pump according to the aspect of thisdisclosure resides in that the motor unit includes an annular stator andan extension member extending from the stator toward the control boardand electrically connected to the stator, and an end portion of thetubular portion and an end portion of the extension member overlap witheach other when viewed in a radial direction of the tubular portion.

According to this configuration, the end portion of the tubular portionfor covering the entire side portion of the control board in the metalportion, and the end portion of the extension member extending from thestator to the side of the control board and electrically connected tothe stator overlap each other in the radial direction of the tubularportion. In this manner, at least one of the tubular portion and theextension member is located around the control board. Accordingly, theoutward emission of the noise of the control unit can be more reliablyreduced, and the noise immunity in the control unit of the electric pumpis further improved.

Another feature of the electric pump according to the aspect of thisdisclosure resides in that at least one of the end portion of thetubular portion and the end portion of the extension member has anelastic portion which is elastically deformable, and the elastic portionis elastically deformed so that the end portion of the tubular portionand the end portion of the extension member are electrically connectedto each other.

According to this configuration, at least one of the end portion of thetubular portion of the metal portion and the end portion of theextension member is elastically deformed, thereby electricallyconnecting both of these to each other. That is, the metal portion andthe extension member are electrically connected to each other.Accordingly, the metal portion can be grounded via the extension memberand the stator. Furthermore, if at least one of the end portion of thetubular portion and the end portion of the extension member is theelastically deformable elastic portion, even if a temperature change,vibration, or shock is applied to the electric pump, a connection statebetween the metal portion and the extension member can be maintained.

Another feature of the electric pump according to the aspect of thisdisclosure resides in that the electric pump further includes a firstconnection member that electrically connects the metal portion and aground pattern of the control board to each other, the motor unitincludes a second connection member which electrically connects thestator and the ground pattern of the control board to each other, andthe stator is configured to be groundable.

According to this configuration, the metal portion and the groundpattern of the control board are electrically connected to each other bythe first connection member. The ground pattern and the stator areelectrically connected to each other by the second connection member.The stator can be grounded. Accordingly, the noise generated in thecontrol board can be released to the ground from the metal portion viathe first connection member, the ground pattern of the control board,the second connection member, and the stator.

Another feature of the electric pump according to the aspect of thisdisclosure resides in that the housing includes a coating portion thatcoats a side of the metal portion which faces the control board, and thecoating portion coats an entire region of the metal portion excluding aconnection site of the first connection member.

In the control board configuring the control unit, various electroniccomponents are usually arranged on the side facing the cover body forcovering the control board. Here, as the electronic component, there mayexist a component having a large projecting height from an installationsurface of the control board. In this case, the electronic component islikely to move close to the metal portion located on the inner surfaceside of the cover body, thereby causing a possibility of shortcircuiting between the metal portion and the electronic component.Therefore, according to this configuration, the housing includes thecoating portion for coating the side of the control board of the metalportion, and the coating portion coats the entire region excluding theconnection site of the first connection member in the metal portion. Inthis manner, the metal portion does not move close to the electroniccomponent, and an insulation distance can be secured between theelectronic component and the metal portion. As a result, voltageendurance characteristics of the electric pump can be improved.

The principles, preferred embodiment and mode of operation of thepresent invention have been described in the foregoing specification.However, the invention which is intended to be protected is not to beconstrued as limited to the particular embodiments disclosed. Further,the embodiments described herein are to be regarded as illustrativerather than restrictive. Variations and changes may be made by others,and equivalents employed, without departing from the spirit of thepresent invention. Accordingly, it is expressly intended that all suchvariations, changes and equivalents which fall within the spirit andscope of the present invention as defined in the claims, be embracedthereby.

What is claimed is:
 1. An electric pump comprising: a pump unit; a motorunit configured to drive the pump unit; a control unit configured tocontrol driving of the motor unit; and a resin-made housing configuredto accommodate the control unit, wherein the housing has a housing mainbody and a cover body, the cover body includes, on an inner surface sidethereof, a metal portion which entirely covers at least one surfaceportion of a control board configuring the control unit, and the metalportion is configured to be groundable.
 2. The electric pump accordingto claim 1, wherein the metal portion has a top surface portion whichcovers the one surface portion of the control board, and a tubularportion which is erected on a side of the control board from aperipheral edge of the top surface portion, and the tubular portionentirely covers a side portion of the control board.
 3. The electricpump according to claim 2, wherein the motor unit includes an annularstator and an extension member extending from the stator toward thecontrol board and electrically connected to the stator, and an endportion of the tubular portion and an end portion of the extensionmember overlap with each other when viewed in a radial direction of thetubular portion.
 4. The electric pump according to claim 3, wherein atleast one of the end portion of the tubular portion and the end portionof the extension member has an elastic portion which is elasticallydeformable, and the elastic portion is elastically deformed so that theend portion of the tubular portion and the end portion of the extensionmember are electrically connected to each other.
 5. The electric pumpaccording to claim 1, further comprising: a first connection member thatelectrically connects the metal portion and a ground pattern of thecontrol board to each other, wherein the motor unit includes an annularstator and a second connection member which electrically connects thestator and the ground pattern of the control board to each other, andthe stator is configured to be groundable.
 6. The electric pumpaccording to claim 2, further comprising: a first connection member thatelectrically connects the metal portion and a ground pattern of thecontrol board to each other, wherein the motor unit includes an annularstator and a second connection member which electrically connects thestator and the ground pattern of the control board to each other, andthe stator is configured to be groundable.
 7. The electric pumpaccording to claim 3, further comprising: a first connection member thatelectrically connects the metal portion and a ground pattern of thecontrol board to each other, wherein the motor unit includes a secondconnection member which electrically connects the stator and the groundpattern of the control board to each other, and the stator is configuredto be groundable.
 8. The electric pump according to claim 5, wherein thehousing includes a coating portion that coats a side of the metalportion which faces the control board, and the coating portion coats anentire region of the metal portion excluding a connection site of thefirst connection member.
 9. The electric pump according to claim 6,wherein the housing includes a coating portion that coats a side of themetal portion which faces the control board, and the coating portioncoats an entire region of the metal portion excluding a connection siteof the first connection member.
 10. The electric pump according to claim7, wherein the housing includes a coating portion that coats a side ofthe metal portion which faces the control board, and the coating portioncoats an entire region of the metal portion excluding a connection siteof the first connection member.